Usually, commercially available utensils used for food cooking present different devices used as temperature indicators.
These indicators are incorporated into the container handles and are intended to provide information regarding the cooking temperature attained or a temperature relating to utensil handling safety on termination of cooking.
Known temperature indicator means present in cooking vessels present coverings containing thermochromatic pigments or liquid crystals, which vary in colour according to the temperature assumed by the pan.
Temperature indicators have also been conceived containing electronic circuits powered by batteries and used to indicate the attained temperature by digital signals, light signals or acoustic signals.
Known temperature indicator systems in food cooking containers have the drawback that if thermochromatic pigments are applied, these lose effectiveness over time due to repeated vessel cleaning.
Battery powered devices have problems relating to device safety, because of evident battery explosion danger when exposed to the heat of the vessel, with consequent food contamination, in addition to maintenance and disposal costs.
Other recently known temperature indicator devices have the drawback of requiring handles of special size and shape containing seats shaped to match the shape of the indicator device.
This fact requires the formation of suitable moulds for handle manufacture, hence increasing the final product cost.
Moreover, this permanent incorporation of temperature indicator devices, in particular those battery powered, can generate problems of impermeabilization or heat resistance when, for example, the cooking vessel is cleaned in a dishwasher.
A further limit of devices pertaining to the prior art is the fact that for each cooking vessel, for example a frying pan, a saucepan or another container, an indicator device has to be permanently mounted in the handle of each individual container, a fact which substantially increases the vessel cost.
EP2361538A1 and EP1889561, incorporated herein by reference, describe cooking vessels according to the preamble of the main claim.